The instant invention relates generally to pilot pressure operated multi-way valves and more particularly to a double-piston, 4-position, 5-way valve for controlling the flow of high pressure corrosive media in a high pressure environment.
Multi-way valves are widely used in hydraulic and pneumatic systems for performing a variety and plurality of coordinated valving functions. Prior art valves however apparently render only 4-way control using 2-position double poppet valves. Also prior art pilot valves are available for handling high pressure media, however there are none, to the knowledge of the applicant that will handle high pressure media in a high pressure environment that is leak tight. Further, many of the multi-way valves are cumbersome and complex in design and in operation to perform their multi-way operation. Prior art valves suffer a lack of reliability when used in a high pressure environment such as is encounted in a ballasting system for a deep submergence vehicle for example. Further in some applications, four or five 2-position, 2-way valves have to be used where the instant valve invention would suffice and be more convenient. Also existing designs of multi-way valves are subject to fouling due to foreign material such as silt getting into the moving parts of the valve.